Method and system for operating rudders of aircraft.



s. rH. cunnss.

METHOD AND SYSTEM FOR OPERATING HUDDERS 0F AIRCRAFT.

APPLICATION rsu-:D rss. la. 1914.

T228380 Patented May 29,1917.

aww/vwo@ GLENN H. Cumiss.

` UNITED sTATEs PATENT oEFIoE. y

GLENN II. CUETIss, OE HAMMONDSPORT, NEW YORK, ASsIGNOE To TIIE CURTISS MOTOR COMPANY, oi IIAMMONDSPOET, NEW YoEx, a CORPORATION OF-NEW IETHOD AND SYSTEM Foa OPERATING EUDDEEs OEAIECEAET.

To all'whom t may concern."

Be it known that I, GLENN H. CURTISS, a citizen of theUnited States, residing at Hammondsport,xeounty of Steuben, State of New York, have invented certain newand useful Improvements in Methods and Systems for Operating Rudders of Aircraft,

of which the following is a specifieatiom' reference being had therein to the aecompanying drawing.

My invention relates to a rudder system particularly adapted for use in connection with the ailerons commonly used in several types of aeroplanes, and is as well adapted for use in connection with warping ailerons as it is with hinged ailerons. As will be apparent however upon a full understanding of my invention, the same is applicable with advantage to any type of air craft steered or balanced by any type rudder.

The prime object of my invention is to reduce to a minimum the power required to operate a rudder against windrpressure, and according to my invention I make use of a new method'which I claim herein as well as the apparatus. This method consists in utilizing the `wind pressure lacting upon the rudder when deflected to lstore up energy, and subsequently using said energy to assist in the succeeding deflection of the rudder. The resulting ease of manipulation is of especial advantage in the .case of unbalanced rudders.

Speaking more specifically in the terms of the apparatus, my invention comprises a` I rudder, a relatively fixed support to which said rudder is attached, and a' tension device interconnecting said rudder and said support at points removed from the line of attachment of said rudder to said support, and normally exerting tension on a line intersecting the line of attachment of said rudder and support, whereby normally said tension device does not bias said rudder in one direction or the other, but when said rudder is deflected, the line of tension of said member is also deflected and shortened and said tension device draws said rudder against wind pressure acting thereon in a degree approximately inversely proportional to the angle of deflection of the rudder.

In the accompanying drawings I show the best forms of apparatus for carrying understood in the art.

.at present known to me.

Specication of Letters Patent. Iatenfed )lay 29, 1917,

.Application filed February 18, 1914. Serial No. 819,521.

out the method of my invention now known to me.

Figure 1 is an end elevation of the supporting surface of an aeroplane equipped with my invention,

.of a modification, and

Fig. fl is a similar View of a second modification.

Connected wlth the supporting surface l0 of Fig. 1 and Fig. 2 is an aileron 11. This aileron 11 is of rigid construction and is connected with the surface 10 by means of hinged ioint 12, but the joint 12 may be of a rigid nature and the aileron 1l a flexible device which vmay be warpedY as well The characteristic of the aileron is that it normally trails in the wind, there being no appreciable wind pressure exerted on one side or the other thereof. This aileron is operated up or down by means of operating cords 13 extending from suitable control levers (not shown) over pulleys 14 and struts 15 connected rigidly with the aileron 11, and at their ends connected with the aileron at points removed from the linel 12 of attachment to the surface 10. iVhen deflected from its normal position by the operator,`

as for instance to the position shown in dotted lines, the wind pressure thereon is a very considerable force, and suflicient-to tire the operator in a very short time in case his machine is a large one and the wind variable. In a number of machines this is overcome by mounting the aileron on an axis passing transversely through its mean center of pressure, or by attaching auxiliary surfaces directly or indirectly thereto. These expedients however cannot be readily resorted to in cases where the aileron is attached directly to one of the planes as in the Farman type. The method of my invention is applicable under all conditions I interconnect the aileron 1l with the supporting surface 10 by means of transverse upper and lower spiral springs 16 and 16 which extend between points 17-18 on the aileron and supporting surface respectively, which points are removed from the line of connection 12 of the aileron @with the supporting surface 10. These springs are so connected that they, when the aileron is in its normal position, lie ysubstantially flatly against or closely adjacent to the surfaces which they interconnect, thereby sullstantially intersecting by their lines of tenby drawing upon the lower'operating cable 13, `the upper spring 16 being bendable, bends around the hinge joint 12 without substantial increase in its tension and without substantial alteration of its effect upon the aileron 11, but the lower spring 16 is freed from the under surfaces of the members 10 and 11y and its line of tension is removed from the line of connection 12 between the aileron y11 and surface 10, whereby the lower spring 16 assists (to a degree depending upon its adjustedtension and inversely proportional to the angle of deflection of the aileron 11) in holding the aileron deflected against wind pressure. Under these conditions the spring 16 contracts, giving out the energy stored within it. The burden upon the operator may by these means be made as small as desired. When the aileron is returned to its normal position, the wind pressure assists the operator and energy is stored up in spring 16', the amount of such energy being a maximum when the spring reaches its full line position with the aileron 11 normal. On a succeeding downward dellection of aileron 11, this stored up energy is given out. The action of the upper spring 16 when the aileron is upwardly deflected is in all respects similar to the action of the lower spring 16', the lower spring 16 in this instance bending at the hinge joint 12 in the same manner as illustrated -for the upper spring in the case described. I have found in actual practice of this invention that every advantage recited is actually attained in its use.

The modification of Fig. 3 consists in foreshortening the springs 16-16, and connecting them at one end with the aileron 11 by meansof links 19-'19 having pivotalconnections 2O with the springs which lie closely adjacent the line of connection 12 between the aileron 11 and the surface 10. These links 19-19 may be rigid or flexible as desired.

The modification of Fig. 4 consists in the utilization of a single tension device 21 in .the form of a compression spring held by a plunger 22 and a casing 23, connected r'espectively to surface 10 and aileron 11. In this modication the line of tension instead of passing approximately through the line ofinterconnection 12 passes exactly through it, the tension device 21 being located either across the ends of the members 10 and 11 or in suitably disposed slots which may be provided as indicated in Fig. 2 in dotted lines. While I have shown and described the best forms of my invention now known to me, I desire to have it understood that many forms may be given myinvention without departing in any wise from its genericspirit, and I desire to cover in the annexed claims all such modifications.

What I claim is: 1. In an aircraft, a rudder system comprising a rudder, a relatively fixed support to which said rudder is connected, and a transversely extending tension device on each side of said rudder'interconnecting the rudder and its support, said tension device comprising a spring and a link respectively pivoted one to the other at a point adjacent to which said rudder is attached and a transversely extending tension device on each side of said rudder interconnecting the rudder and its support, said tension device comprising a spring hinged at a point adjacent the line of attachment of Said rudder and said support.

3. In an aircraft, a rudder system comprising a rudder, a relatively fixed support to which said rudder is connected, said rudder being when deflected biased to a normal position by wind pressure, and a trans, versely extending bendable tension member on each side of said rudder interconnecting the rudder and its support and normally exerting tension on lines passing close to the line of connection between said rudder and its support, each member being bendable about said"line without substantial alteration of the force exerted on said rudder when the rudder is moved in a prescribed direction, and each on the other hand when the rudder is deflected in the opposite direction occupying a position removed from said line of connection and exerting a force biasing said rudder against wind pressure.

4. In an aircraft, a rudder system comprising a rudder, a relatively fixed support to which said rudder is connected, said rudder being when deflected in either direction biased to a normal position by windpressure, and a transversely extending tension device on each side of said rudder interconnecting the rudder and its support, the tension of said devices while the rudder is in but when said rudder is direction from normal the being destroyed and normal position, moved in either equilibrium of tension a draft applied erating tension of one device or the other -in the direction in which it has been moved.

5. In an aircraft, a rudder system comprising a rudder, a relatively fixed support to which said rudder is attached, and a transversely extending tension device on one side of said rudder interconnecting the rudto therudder by prepondder audits support, said tension device comprising a spring having a hinge joint adjacent the line of attachment of said rudder and said support to permit deiection of said rudder from its normal position.

In testimony whereof I aiix my signature in presence of tWo Witnesses. y

GLENN I-I. CURTISS. Witnesses:

H: 5C. GENUNG, LYMAN J. SEELY. 

